Rotary pump



1931- R. M. BLACKMER 1,820,009 I ROTARY PUMP Filed April 2. 1928 2Sheets-Sheet l 4 A? 30 a5 .3? 37 j ,4

woenloz L umulfll Ma Aug. 25, 1.931. R. MJBLACKMER ROTARY PUMP FiledApril 2, 1928 2 Sheets-Sheet 2 cylinder 14. This shaft has securedthereto Patented Aug. 25, 1931 UNITED STATES PATENT OFFICE ROBERT 'M.BLACKMER, OF IDIlilTItO IT, MICHIGAN, ASSIGNOR T0 STEPHEN A. GRIGGS,

OF DETROIT, MICHIGAN ROTARY PUMP Application filed April 2,

The invention relates to rotary pumps and more particularly to a type ofpump wherein the rotor is provided with a-rcuate shaped buckets o-rvanes projecting from the periphery thereof.

One of the objects of the invention is to provide a pump wherein thecylinder and cam are constructed of a single casting, the cam portionbeing integral with the other portions of the housing. Another ob ect isto provide a construction for introducing the fluid into the spacebetween the vanes of the rotor by conducting the fluid around the endsof said vanes. A further object is to so construct the cylinder, cam andhead of the pump as to facilitate the manufacture on a large productionscale at a low cost.

With these'and other objects in view I have provided the improved pumpconstruction hereinafter fully described and illustrated in theaccompanying drawings, wherein Y Figure 1 is a cross section through theFigure 2 is an axialsection therethrough;

Figure 3 is an end view of the pump with the head removed;

Figure 4 is an end view of the head;

Figure 5 is a perspective view of the pump with the head withdrawn fromthe cylinder to show the fluid ports. I

Referring -now to the embodiment of my invention as illustrated in thedrawings, the pump comprises a casing 10 mounted on a base 11 andprovided with suitable inlet and outlet'fittings 12 and 13 respectivelywhich as shown are arranged at substantially right angles to each other.The casing has a hollow interior forming a cylinder 14, the oppositeends of which are provided with annular flanges 15 and 16. 17 and 18 arecylinder heads each havingan inwardly projecting ring 19, the outerdiameter of which is adapted to fit the cylinder 14. The heads areretained in position abutting thefianges 16 and 15 by suitable meanssuch as the bolts 20. v

21 is the rotor shaft journaled in the heads 17 and 18 and extendingthrough the 1928. Serial No. 266,648.

a cylindrical rotor 22, the outer diameter of which is smaller than thecylinder 14 leav- Y ing an annular space 23 therebetween. The rotor isprovided with a series of slots 24 which in transverse cross. section asshown in Figure 1 appear as circular arcs. These slots extend lengthwiseof the rotor for the greater part of its length terminatingsubstantially at the plane of the inner face 25 of the'ring 19. Each ofthe slots 24 intersect the periphery of the rotor at two spaced pointsas indicated at 26 and 27 and the number of slots with which the. rotoris 1 provided may be varied as desired, providing a symmetricalarrangement is maintained. As illustrated there are four slots althoughthere may be more or less than this number in some instances. Forconvenience in manufacture the rotor 22 has the slots extendingcompletely through one end thereof, thereby permitting the slots to beformed by an end mill. For closing the open ends of the slots there isprovided the end p1ate'28 secured to the rotor by the machine screws 29.This plate is of the same diameter as the rotor and is of substantiallythe same thickness as the ring 19 on the head 18.

Extending across the cylinder 14-between the inlet and outlet of thepump is in abutment or cam 30 which has a portion 31 ofsubstantially'the same radius as the radius of the rotor 22; Thisportion 31 is of sufficient length to overlap the two adjacent slots inthe rotor. From the portion 31 the surface of the abutment is inclinedgradually in opposite directions as indicated at 32 and 33 until itmerges with the cylinder 14. In each of the arcuate slots 24 there arearranged vanes or buckets and in accordance with my invention there arepreferably two vanes in each slot. These vanes which are indicated bythe-numerals 34 and 35 are curved transversely to conform with thearcuate slots and are preferably constructed to fit these slots snugly.The inner edges 36 and 37 of the vanes are preferably fiat, while theouter edges 38 and 39 are curved in such a manner that when they arearranged withinftheslots so as to be substantially flush with the outerperiphery of the -width and the widths are determined so face 31 of theabutment.

that when one vane is riding upon the surface 31 and the other vane isriding upon the surface of the cylinder 14, the inner edges of the twovanes will just be in contact. In order to permit the separation of thetwo vanes 34 and 35 when neither vane is in contact with the abutment, Ihave provided vent passageways or bleed ports 40'extending through therotor between its outer periphery and the central portion of each of thearcuate slots. These passagewa s are of a diameter such as to permit'theuid to pass outwardly therethrough when the vanes are forced intocontact but are restricted to such an extent as to prevent anyappreciable noise when the contact takes place.

The cam or abutment 30 is in accordance with the present invention madeintegral with the casing 10 as illustrated in Figure 1. Therefore thecasing does not contain a true cylindrical inner surface but thissurface is cylindrical for only a portion of its circumference, theremainder being of the cam shaped contour described above. When thecasing is constructed in this manner it is cast to the approximatedimensions and the interior is thereafter broached to finish theinterior surfaces.

Extending laterally of the inlet fitting 12 is a fluid passageway 42.This passageway extends for the full length of the cylinder and thewidth of the passageway is (as shown in Figure 1) such as to extendcircumferentially from a point beyond the inclined cam surface 32 to apoint 0 osite the surimilarly there is a fluid passageway 43 extendinglaterally of the outlet fitting 13 and arranged on the opposite side ofthe abutment 30. The end .of the cylinder has two segmental slbts 44 and45 cut into the cam portion thereof as best shown in Figure 5. Theseslots communicate respectively with the fluid passage- 1 ways 42 and 43and are separated by an inwardly projecting lug 46, the inner surface 47of which is of the same radius as the cylinder 14.

As heretofore stated, each of the heads is provided with an inwardlyprojecting ring 19 adapted to fit the cylinder 14. This ring has acontinuous portion 19a for engaging the circular portion of the cylinder14 and is cut away for the remainder of the circumference except for ala 19?) disposed midway between the ends 0 the continuous portion. Theouter surface of the lug 19b is adapted to engage the inner surface 47'of the lug 46. When the head is assembled to the cylinder the outersurfaces of the rin 19 and the lug 19b engage the inner sur aces of thecylinder. faces of thering 19 and lug 19b serve to house the rotor 22.The flat surface 190 of the ring engages the edges of the vanes andmakes a fluid tight joint therewith. The construction as above describedis such that the fluid may enter and leave around the edges of the vanesby reason of the cut away portions in the cylinder and in the ring onthe head. g I

In the operation of the pump the rotor is driven by any suitable meanscausing the vanes v to be moved around the cylinder.' The fluid enteringthrough the inlet fitting 12 passes laterally through the passageway 42to the opposite ends of the rotor and then radiallyinward through therecesses 44 and the cut away portions of the ring 19 past the ends ofthe vane into the space A bounded by the ends of the vanes 35aand 34a asindicated in Figure 1. As the rotor is rotatively advanced the vane 35wrides down the inclined cam surface 32, being forced outwardly by thecentrifugal force of the rotating rotor.

Since the vane 35! is maintained in contact The inner sur- 1 tact withthe cooperating vane and expelling any. fluid trapped between the vanes.The fluid is then forced outwardly through the recess 45 and fluidpassageway 43 by reason of the second of the two vanes riding up theincline 33. This cycle is repeated during each rotation of the rotor andeach set of vanes carries a certain amount of fluid between the inletand outlet conduits.

What I claim as my invention is:

' 1. In a pump, a cylindrical housing, a

rotor within said housing, vanes extending outwardly from said rotorengaging the cylindrical surface of said housing, a cam abutmentextending across a portion of said cylindrical housing, heads at theopposite ends of said housing having recesses for engaging said rotor,rings on said heads engaging the end edges of said vanes, said ringsbeing cut away on opposite sides of said abutment and inlet and outletpassageways communicating respectively with the cut away portions ofsaid rings on the opposite sides of said abutment.

2. In a rotary pump, a cylinder, an abutment extending across a portionof said cylinder, a rotor journaled concentrically .of

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said cylinder, vanes extending outwardly from said rotor, heads engagingthe opposite ends of said cylinder, inwardly projecting rings'on saidheads each having an outer surface for engaging said cylinder and aninner surface for engaging said rotor, said ring being cut away to formradial passageways and inlet and outlet ports communicating with saidradial passageways.

3. In a pump, a casing having a cylindrical portion and a cam shapedabutment extending across the same, a rotor mounted concentrically ofsaid cylindrical portion, vanes extending outwardly from said rotor, apair of heads at opposite ends of said cylinder, each head having a ringengaging said cylindrical portion, said ring having an interior surfacefor engaging said rotor, said ring having two cut away portions onopposite sides of the central portion of said abutment and said cylinderhaving segmental slots communicating .with the cut away portioris ofsaid ring.

4. In a rotary pump, a housing having an interior surface circular incross section for a portion of its circumference and cam shaped for theremaining portion, a cylindrical rotor having vanes projectingtherefrom, heads at the opposite ends of said casing, each head having aring engaging said housing, said head having a bearing surface for theend of said rotor, said cam being provided with segmental recesses onopposite sides of the central portion thereof and said ring being cutaway to correspond with said recesses and longitudinal passagewaysthroughsaid housing communicating with the respective recesses.

5. In a rotary pump, a housing having an interior surface circular incross section for a portion of its circumference and cam shaped for theremaining portion, a cylin- .drical rotor having vanes projectingtherefrom, heads at the opposite ends of said casing, each head having aring engaging said housing, said head having a bearing surface for theend of said rotor, said cam being provided with segmental recesses onopposite sides of the central portion thereof and said ring being cutaway to correspond with said recesses, longitudinal passagewaysextending the full length of the housing communicating with therespective recesses, and inlet and outlet ports communicating with saidlongitudinal passageways.

In testimony whereof I aflix my signature.

ROBERT M. BLACKMER.

